gm/bitmapfilters.cpp

/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "gm.h"

namespace skiagm {

static void make_bm(SkBitmap* bm) {
    const SkColor colors[4] = {
        SK_ColorRED, SK_ColorGREEN,
        SK_ColorBLUE, SK_ColorWHITE
    };
    SkPMColor colorsPM[4];
    for (size_t i = 0; i < SK_ARRAY_COUNT(colors); ++i) {
        colorsPM[i] = SkPreMultiplyColor(colors[i]);
    }
    SkColorTable* ctable = new SkColorTable(colorsPM, 4);

    bm->setConfig(SkBitmap::kIndex8_Config, 2, 2);
    bm->allocPixels(ctable);
    ctable->unref();

    *bm->getAddr8(0, 0) = 0;
    *bm->getAddr8(1, 0) = 1;
    *bm->getAddr8(0, 1) = 2;
    *bm->getAddr8(1, 1) = 3;
}

static SkScalar draw_bm(SkCanvas* canvas, const SkBitmap& bm,
                        SkScalar x, SkScalar y, SkPaint* paint) {
    canvas->drawBitmap(bm, x, y, paint);
    return SkIntToScalar(bm.width()) * 5/4;
}

static SkScalar draw_set(SkCanvas* c, const SkBitmap& bm, SkScalar x,
                         SkPaint* p) {
    x += draw_bm(c, bm, x, 0, p);
    p->setFilterLevel(SkPaint::kLow_FilterLevel);
    x += draw_bm(c, bm, x, 0, p);
    p->setDither(true);
    return x + draw_bm(c, bm, x, 0, p);
}

static const char* gConfigNames[] = {
    "unknown config",
    "A8",
    "Index8",
    "565",
    "4444",
    "8888"
};

static SkScalar draw_row(SkCanvas* canvas, const SkBitmap& bm) {
    SkAutoCanvasRestore acr(canvas, true);

    SkPaint paint;
    SkScalar x = 0;
    const int scale = 32;

    paint.setAntiAlias(true);
    const char* name = gConfigNames[bm.config()];
    canvas->drawText(name, strlen(name), x, SkIntToScalar(bm.height())*scale*5/8,
                     paint);
    canvas->translate(SkIntToScalar(48), 0);

    canvas->scale(SkIntToScalar(scale), SkIntToScalar(scale));

    x += draw_set(canvas, bm, 0, &paint);
    paint.reset();
    paint.setAlpha(0x80);
    draw_set(canvas, bm, x, &paint);
    return x * scale / 3;
}

class FilterGM : public GM {
    bool fOnce;
    void init() {
        if (fOnce) {
            return;
        }
        fOnce = true;
        make_bm(&fBM8);
        fBM8.copyTo(&fBM4444, SkBitmap::kARGB_4444_Config);
        fBM8.copyTo(&fBM16, SkBitmap::kRGB_565_Config);
        fBM8.copyTo(&fBM32, SkBitmap::kARGB_8888_Config);
    }
public:
    SkBitmap    fBM8, fBM4444, fBM16, fBM32;

    FilterGM() : fOnce(false) {
        this->setBGColor(0xFFDDDDDD);
    }

protected:
    virtual SkString onShortName() {
        return SkString("bitmapfilters");
    }

    virtual SkISize onISize() {
        return make_isize(540, 330);
    }

    virtual void onDraw(SkCanvas* canvas) {
        this->init();

        SkScalar x = SkIntToScalar(10);
        SkScalar y = SkIntToScalar(10);

        canvas->translate(x, y);
        y = draw_row(canvas, fBM8);
        canvas->translate(0, y);
        y = draw_row(canvas, fBM4444);
        canvas->translate(0, y);
        y = draw_row(canvas, fBM16);
        canvas->translate(0, y);
        draw_row(canvas, fBM32);
    }

private:
    typedef GM INHERITED;
};

//////////////////////////////////////////////////////////////////////////////

static GM* MyFactory(void*) { return new FilterGM; }
static GMRegistry reg(MyFactory);

}